Figure 5.

Enhanced immune control of tumor growth by frequent administration of EtxB. (A) Schedule for immunization and EtxB (or PBS) for experiments shown in B–F. (B and D) Unimmunized or (C, E, and F) Vac-LMP2A-immunized mice were injected with Renca-LMP2A tumor cells 11 days later. Mice were then injected with either 50 μg EtxB (•) or PBS (○) two times per week up to day 10, and then daily from day 11 to day 18. Tumor growth was monitored for 18 days, except for the Vac-LMP2A-immunized EtxB-treated mice in which tumors were monitored for a further 10 days without EtxB (as indicated). (B) Tumor volumes for individual mice in the unimmunized group or (C) the immunized group. (D) Mean tumor volumes for the unimmunized or (E) Vac-LMP2A-immunized group of mice. One-way ANOVA (analysis of variance) was used to compute the P-value in E. (F) Bar graph showing significant differences in tumor volumes of EtxB-treated (▪) compared to PBS-treated controls (□) on days 14–19. Data is presented as mean + SEM. Two-tailed Mann–Whitney nonparametric test was used to compute the P-values; *P ≤ 0.03; **P ≤ 0.003.